The vote was held without a CBO score on the revised version of the American Health Care Act. The CBO'sanalysis of the original AHCA draft found an additional 24 million Americans would be uninsured in the next 10 years while also saving $337 billion in federal budget deficits.

Dive Insight:After years of promising to repeal the ACA,the Republican party took a major step toward that goal Thursday with a bill that will revamp health insurance for most Americans.

The revised AHCAdrastically changes the individual insurance market as well as the Medicaid. As currently written, Medicaid expansion would be phased out and the public program would take a $880 billion hit over 10 years. The measure allows states to circumvent essential health benefits requirements, potentially exposing those with pre-existing conditions to higher out-of-pocket costs.

The GOP was determined to bring the measure to a floor vote. Republicans failed to hold a vote on the measure in March when the legislation was first drafted. However, ACA supporters had a short honeymoon for AHCA's failure as Republicans quickly returned to the bill in hopes to make good on their campaign promises to repeal the ACA.

However, most of the influential industry associations such the American Medical Association and the American Hospital Association oppose the AHCA,“The bill passed by the House today will result in millions of Americans losing access to quality, affordable health insurance and those with pre-existing health conditions face the possibility of going back to the time when insurers could charge them premiums that made access to coverage out of the question,AMA President AndrewGurmanstated after the vote."Action is needed, however, to improve the current health care insurance system. The AMA urges the Senate and the administration to work with physician, patient, hospital and other provider groups to craft bipartisan solutions so all American families can access affordable and meaningful coverage, while preserving the safety net for vulnerable populations.”

It was a morning of intense debate and a few late defections. Democrats did not mince words, and told the GOP their bill will result in unnecessary deaths. “Affordable healthcare is civil right and a fundamental right for everyone in our country, not just the privileged few," Rep. Nancy Pelosi (D-CA) said on the house floor before voting began.

A recent "yes vote" convert was the influential Rep. Fred Upton (R-MI),who switched after tweaking an amendment so the legislation would include high-risk pools and fund them with $8 billion. Multiple health policy experts,however,say that would not be nearly enough to adequately protect people with pre-existing conditions.

Competing interests among Senate Republicans could significantly complicate efforts to partially repeal and replace the 2010 health care law. But despite the influence individual members will have, two have enhanced sway among their colleagues: Orrin G. Hatch of Utah and Lamar Alexander of Tennessee.

While leadership is expected to have a heavy hand in the process, the two senior lawmakers, aschairmen of the committees of jurisdiction, will be instrumental in driving support for any measure the chamber considers. Jockeying between the two panels over authority, however, could be a detriment to any serious attempts at an overhaul of the U.S. health care system.

The legislation being considered in the House is widely expected to change significantly inthe Senate, and coordination between Hatch and Alexander will be critical. The two wield enormous influence over any health care legislation — Hatch as chairman of the Senate Finance Committee and Alexander as leaderof the Health, Education, Labor and Pensions panel. And while members do not expect the measure to go through the formal committee process, the opinions of Hatch and Alexander carry significant weight.

“If they oppose something, it’s not going to happen, that’s the respect they command in the conference. On the other hand, if they are behind it, people will take a second look even if initially they were not sure,” Louisiana GOP Sen. Bill Cassidy said.

Uniting the factions

Part of their roles will be corralling a Republican conference that has become even more divided on the path forward on the health care law, a hurdle Alexander largely dismissed.

“There are many different views in the Senate,” hesaidWednesday. “I think the most important thing is for [the House] to get it right and taking the time to get it as good a bill as possible makes it easier for us in the Senate.”

But a senior GOP lawmaker, speaking on background in order to discuss internal strategy, said the Senate was prepared to act in short order on a repeal bill if the House hadpassed it earlier this year — as initially planned. The delay, the senator said, has only served to grow the opposition among factions in the Republican caucus.

Cassidy and fellow Republican Sen. Susan Collins of Maine, for example, continue to advocate their own legislation, a bill that some of their GOP colleagueswould likely strongly oppose. Conservatives, such as Sens. Ted Cruz of Texas, and Mike Lee of Utah, have also been very involved in the House effort and have urged the House Freedom Caucus to push for changes that drove away some moderates in that chamber and would likely have a similar result in the Senate.

With such a thin margin — Republicans can only afford to lose two votes on the legislation to pass it under the expedited budget procedure known as reconciliation — any defections are significant. Senate Majority Leader Mitch McConnell, for his part, acknowledges the difficulty facing the chamber on health care legislation.

“We don’t want to give up on this,” the Kentucky Republicantold reporters Tuesday. “When they send it over here, it’ll be a real big challenge on the Senate side as well.”

Republican aides expect McConnell to wield significant control over the initiative, partiallyin an attempt to avoid the drama that has plagued the House.

Among anumber of actions he has taken since the start of the year, aides say McConnell has organized a working group of roughly a dozen GOP senators to discuss issues related to the repeal of the health care law. Members of the group include Hatch, Alexander, Cruz and Lee, as well as Colorado’s Cory Gardner, Arkansas' Tom Cotton and Pennsylvania’s Patrick J. Toomey.

Toomey, when asked about the group, said meetings had just begun.

Senate Republican Policy Chairman John Barrasso of Wyoming and Senate Budget Chairman Michael B. Enzi of Wyoming, whose panel has worked closely with the House on its effort up until this point, are also expected to play a large role and both are said to serve on the working group.

Crucial contributions

But the input of Hatch and Alexander will likely be the most crucial. Legislation that eventually became the 2010health care law advanced in the Senate the previous yearlargely because of the close coordination between then-Finance Chairman Max Baucus of Montana, Sen. Edward M. Kennedy of Massachusetts, then chairman of HELP, and his surrogate, Sen. Christopher J. Dodd of Connecticut. Privately, GOP aides also attribute the chaos in the House in part to the effort becoming a largely off-committee initiative, an uncommon occurrence in the Senate.

Despite the significant role they will play in the process, Hatch said he and Alexander have not engaged in any serious discussions regarding the bill’s future in the Senate.

“We’ve had some initial conversations, but not any definitive ones,” the Utah Republican said Tuesday.

As Finance chairman, Hatch would be responsible for legislation pertaining tomost aspects of the health care law addressed in the repeal bill and is expected to exercise that right. The panel has been very involved with the House effort behind the scenes and coordinated closely with leaders in the chamber on early legislative drafts.

Hatch “has been quietly working with members to help set expectations and ensure Republicans don’t over-promise and under-deliver with this exercise,” one Senate aide said.

But Alexander has been particularly vocal as the House’s repeal effort has advanced. He gave several floor speeches on the initiative and called for the development of plan to replace the law before its repeal, a stance at odds with some Republicans.

And some GOP senators point to Alexander, not Hatch, as the main driver behind any health care overhaul.

“Once Lamar is able to step in and work some of his magic, I think you’re going to see things start to move,” South Dakota Sen. Mike Rounds said. “Sen. Hatch is going to have a lot say about the finances. … But before you can do that, you’ve got to know what you want for your end result and I think that’s where Lamar Alexander will have a real opportunity.”

Democrats also point to Alexander’s working relationship with Sen. Patty Murray of Washington, the top Democrat on HELP, as a possible route to a bipartisan compromise on health care.

“On a very contentious issue, which is education, Chairman Alexander and ranking member Murray led the HELP Committee to a very strong bipartisan result and I believe such a thing is possible on health care,” Rhode Island Sen. Sheldon Whitehouse said.

Potential complications

But while Murray has expressed interest in opening discussions on the topic, she said conversations could not occur while Republicans continue in their attempt to repeal the law.

“When they take repeal off their plate, then we’ll talk,” she saidWednesday.

While a bipartisan effortwould be a massive lift, many areas of the law that couldbe addressed in any bill would fall outside the jurisdiction of HELP, meaning buy-in from Hatch and Sen. Ron Wyden of Oregon, the top Democrat on Senate Finance, could be necessary.

Asked about the lines of jurisdiction between the two committees on health care, Hatchcalled them “pretty well-established.”

“About 95 percent of that is ours,” he said. “[Alexander] likes to get whatever jurisdiction he can and I can’t blame him for that.”

Still, there are several areas within HELP’s jurisdiction that Alexander and Murray could tackle related to the cost of insurance and the regulation of insurance companies.

Updated iterations of the current GOP repeal bill mightinclude more provisionsunder the purview of the panel, like an amendment from Reps. Tom MacArthur of New Jersey and North Carolina's Mark Meadows, who leads the House Freedom Caucus, allowing states to waive several of the law’s requirements related to what insurers must cover. It remains to be seen whether such an amendment can even meetthe Senate rules governing reconciliation. Democrats say it won’t.

And should it reach the floor, any lawmaker — Republican or Democrat — would be allowed to introduce an amendment based on the rules governing reconciliation. That makes guidance from veteran lawmakers such asHatch and Alexander all the more important.